kirjauduajax.php

<?php
session_start();
$json=isset($_POST["user"]) ? $_POST["user"] : "";

if (!($user=tarkistaJson($json))){
    print "Täytä kaikki kentät";
    exit;
}

mysqli_report(MYSQLI_REPORT_ALL ^ MYSQLI_REPORT_INDEX);

try{
    $yhteys=mysqli_connect("db", "root", "password", "kahvio");
}
catch(Exception $e){
    print "Yhteysvirhe";
    exit;
}

$sql="select * from credentials where username=? and password=SHA2(? , 256)";
try{
    $stmt=mysqli_prepare($yhteys, $sql);
    mysqli_stmt_bind_param($stmt, 'ss', $user->username, $user->password);
    mysqli_stmt_execute($stmt);
    $tulos=mysqli_stmt_get_result($stmt);
    if ($rivi=mysqli_fetch_object($tulos)){
        $_SESSION["credentials"]="$rivi->username";
        if ($rivi->admin) {
            print "admin";
        } else {
            print "user";
        }
        exit;
    }
    else 
    mysqli_close($yhteys);
    print $json;
}
catch(Exception $e){
    print "Jokin virhe!";
}
?>


<?php
function tarkistaJson($json){
    if (empty($json)){
        return false;
    }
    $user=json_decode($json, false);
    if (empty($user->username) || empty($user->password)){
        return false;
    }
    return $user;
}
?>